Spiral tuner



R. J. AUST 2,666,906

SPIRAL TUNER 2 Sheets-Sheet l Jan. 19, 1954 Filed April 18. 195o M w ai W M V Y M| gag .Z m 1 u 1W M m r Q www x w Q n I 0 ma M 1 M M INVENTOR. BY aer f us TMR/w57 R. J. AUST SPIRAL TUNER Jan. 19, 1954 2 Sheets-Sheet 2 Filed April 18, 1950 Patented Jan. 19, 1954 UNITED STATES PATENT OFFICE SPIRAL TUNER Robert J. Aust, Indianapolis, llnd., assigner :to l. R. Mallory &. Co., Inc., Indianapolia Ind., a corporation ofDelaware Application-,April I8, 1950,-S'eria1zNo'. 156,595

(Cl. 33e-4139) 7 Claims.

This invention relates generally to electromagnetic Wave tuning devices operative over la wide band of high frequency ranges Vandrhasspe-l cifcapplication to such devicesfincluding means and methods for inductively tuning high fre-- fluencyapparatusy and theflilre.

Heretofore, inductance tuning devices have ordinarily comprised a 'helical` coilor -loarey Wire Wound on a .rotatable-coil form. This coil yWas engaged by a conductive nib on .afcontactor assembly which was slideable longitudinally in response to rotation of. the coil. In thismanner,

the contact nib moved along the coil thereby' is to provide an. improved.spiral wound tuningv device adapted for inductive tuning a resonant circuit in the reception of `ultra `high frequency electromagnetic signals.

Still a further object of the present invention is to provide a new and. novel tuning :device wherein the inductive coil arrangement utilized thereon comprisesa spiralribbon wound conductor maintained. upright @nan insulative base.

Yet another .object of .the invention `is tojprovide, in a spiral wound inductive tuning device, a contactor element slideably rotated onsaid spiral wound inductive tuner and. making. .contact therewith by means or" a link Ajointassembly.

Still another objectof the present-invention is a spiral. Wound inductive tuning device `having closely spaced terminal strips so as to reduceinductive effects therein.

Yet another object of` the .present invention provides, in a tunerof theinductive-type, aspira-l wound conductor firmly molded in an insulative bases@ asto provideia unidueinductorassembly adapted to bev positioned in relatively compact andclosequarters.

Although, the novel features :Whiclrare-ioharac teristic of the invention are set {forthmore :in detail in the claims appendedvhereto, the nature 2 and .scope Tof :the invention may zbe 1be'tter1understoodY by reference :to` the followingl deSClptOll takenv in connection 4with the accompanying drawingiorrning Vapart thereof', in which. a. specicernbodiment haslbeen setfforth fory purposes of .illustrationl In the drawing:

Figure 1.. isa top planV view Vof an embodiment of. the .invention-of anew spiral Wound ribbon conductor tuning device;

Figure. 2- is va side view of the present invention,V with. portions thereof-shown .iny elevation, adapted lfor .usev .in illustrating thea-novell feature of the contactor and `terminal assembly of the spirallwoundtuner of the present invention;

Figure 3 is a bottom viewroft the embodiment of. the inventionasshownin- Figures,k l and; Zand asadapted*toI illustrate the terminal` constructiony thereof.;

vEigureA .4..is asectionalized `vievv -of the invenn tion astake. alongline 4-4-fof Figure Zfespecially adapted tovill-ustrataalong With-.Figure 5 below, the. novel spiral .woundconstruction of 'theftuner assembly;

Eigure .is anenlarged cross-.sectional 'view of.

the. one of the.spiral..\voundsectionsof the above tuner invention adapted to illustrate the mount ing-of. the-spiral rilolzlon.conductorsv embedded in an insulative base;

v Figure 6 isa viewof the base sectionY maintainingthespiralconductor of theftuner as taken along line. S-Eof Figure; and

Figure 'ZY isa .cross-sectional. view-of the Stoll mechanisrnutilized inthe present invention for limiting theexcursion Vof. vthe contacter element along .the spiral.. Wound Vccnnductors embedded .in

the baseelements of the-timer.

In the lfollowing description certain specific terms are Iused forconvenience inreferring to the various details of the invention. These terms are to rhe interpreted. however, in .accordance with therstateofthe art.

Generally speaking, .thepresent invention relates :toeontinuously yvariable tuning devices of theinductance type. In.accordance with the invention a spiral Wound.conductor having-a ribbon .congurationrhas one of its edges vertically embedded in an insulative base, such as, aplastic, and held 4in anupright mmner therein. 'The multiple turns :of thel conductor are vclosely spirally wound withinleach otherand'xedly re tained in: ythe .insulator base. A novel :hinged contact snfmfhaving a `Wiper isv then lallowed to ride :onutherouteredgesoi theconduotor lin an es* sentiallyfexpanding mannerfdependent upon the angular relationship formed between the movable hinged separate portions thereof. Moreover, these portions act so that in closely moving toward each other the inductive eiTect-s of each arm operates so as to substantially cancel each other. This novel construction provides a tuner which simplifies dial or channel indicator arrangements and reduces the usual number of turns required for a tuning knob to obtain the same frequency vs. tuning characteristics. Thus, an essentially compact, simple and efficient tuner has been provided.

The variable inductance tuning device I IJ, as shown in the drawings, Figures 1-3, comprises a front support bracket or end plate I I, a back end plate or support I2, and a plurality of tuner sections I3-I6 which are retained in cut-outs I1-I1-I1I1 of base plate I8. Each of these tuner sections individually includes one of the terminal bases I9-22 adapted to seat individual spiral wound coils 23, 26 asimbedded in coil forms 21, 38. Individual contactor means 3| are electrically connected to the coils so as to rotate with a shaft assembly 80 extending through each of the coils and coil forms. The amount or extent of angular displacement of the shaft within predetermined limits is controlled by means of a plurality of stop members 28 centrally mounted on the shaft. Each of the terminal plates, as above. includes a pair of terminals such as 31, 38, adapted to be connected to the coils, as will nereinafter appear. A clamp strap 39 and a plurality of metal partitions 40, 43 are provided to aid in the xed support of the coil forms on the terminal bases to aid in the electrical shielding of each of the spiral wound coils.

Since the tuner sections are substantially alike and are constructed in a similar manner. a description of one of said sections will be deemed to apply as well to the other of said sections. For example, tuner section I3 comprises a portion of the tuner between partition or shield 48 and bracket II. A cut-out I1 (Figures Lle-b), substantially of rectangular configuration is formed in base plate I8 of said tuner I8. Base plate I8 has small portions bent up to form side flaps |49 and I4I.

Terminal base I9, which may be fabricated of an electrically insulative material such as plastic, has a conguration such that a portion of its thickness forms an upper level I having a diameter larger than the diameter of the cut-out formed in base plate I8, while its remaining thickness forms a lower level 50 for the terminal base I9 and has a smaller diameter which is adapted to iit into the said cut-out formed in plate I8. In this manner, a shoulder 240 is formed for terminal base I9 and is adapted to sit on the inside surface 48 of plate I8 in a substantially tight fashion.

Terminal base I9, as stated, has a portion thereof carved out to form a lower inside level 50 and an upper level 5I. A plurality of slots 52, 53 are formed and cut through the said inside level, one of which slots. for example, has a T-shaped configuration. Both of the slots are adapted to retain and allow terminals 31 and 38 to penetrate therethrough.

Coil form 21 (Figures 4-6) has a circular central section 54, and extension 55 depending therefrom. Extension 55 has a surface 56 and is connected to central section 54 in such wise that a pair of shoulders 51 and 58 are formed in the coil form. The said extension 55 fits into slot 52 with shoulders 51 and 58 resting on the upper duotor 60 contained between its ends 6I, 62. Conductor 60 has edges 63, 54 of extremely narrow thickness and thus presents a thin ribbon-like configuration. Conductor 80, which may be of a silver coated copper construction, is spiral wound to form a number of turns 65, 65 etc. to comprise coil 23. The conductor, and the individual turns thereof, outwardly extend from coil form 21 substantially at right angles thereto and are retained thereby in a rigid, essentially inextricable fashion by having edge B4 of conductor 60 imbedded in grooves 19, 18 etc.

At end 6I of conductor 60 a high side terminal 31 is connected. Terminal 31 generally has a C-shape configuration and includes a central section 15, a lip section 18 and a solder lug section 11. Solder lug section 11 fits through slot 52 of terminal base I9 and is maintained in a groove formed in under surface 19 of coil form 21. This surface 19 has a plurality of strengthing ribs formed thereon and is free from any of the turns of conductor 68. Lip I6 makes connection to end 6I of conductor E9 by passing through aperture 1I from the under surface 19 of coil form 21. Low side terminal 38 is tted through slot 53 in terminal base I9 and makes contact with conductor 6l) at end 62 thereof, as hereinafter described.

Through the central aperture of the coil forms, for example, aperture 1I, there is extended a rotatable shaft assembly or driver means 88; Shaft assembly 8U comprises two intertted sections 8I, 82 with center shaft section 8| adapted to nt within a bore formed in the front main shaft section 82. A groove 9| annularly cut Within shaft section 8| forms a collar 83 which is adapted to aid in the retention of a lock springr 84 therewithin. The mounting means for the shaft assembly comprises a mounting bracket II having a face plate 85, sides 86, 81 and ledges 88, 89 integrally formed respectively from said sides but positioned at substantially right angles thereto. The entire end bracket is then staked or otherwise fastened in an upright fashion to base plate I8. To aid in the positioning of shaft assembly 80, one of the shields I22 has a plurality of struck-out ledges |23 which are adapted to rigidly hold a spring |24 against center shaft 82. Face plate 85 of bracket I I has its center thereof bulged outwardly to form a bearing surface |00 while its under surface is thus depressed so as to tlock a spring 84 included in a groove 9| against the surface. An aperture 98 penetrates this said bearing surface and is adapted to receive in a substantially tight fashion a bushing positioned against said bearing surface |80. Main shaft section 82 is supported within bushing 95. A thrust spring IUI fits over shaft section 82 against bushing 95 and supplies needed thrust for stop members 26 which includes a plurality of intermediate stop members |82, I 02' having struck-up ears |83, |84 for engaging each other to rotate the individual stops between limits formed at the top surface thereof. The intermediate stop members ;tactor assemltily thereby.

rare contained .between locatmgstoprmernber .L05

and-.ardriverastop member .|66 :sosas-to-.determine displacement of' shaft .assembly 80.

Asrseen, each oflthe tunen-sections hasaportionfoi center shaftk .8| :adapted toznt rthrough. an aperture inthe coil form so. as .to .rotate .a con- Contactorassembly. 3|

comprises a :shaft clamp its, awhich has .a plu- .rality'.of.Lintegrallyiformed,ears l'ladapted .tot

`within* associated grooves in Contact arm till, which may. be bent so Aas to 'firmly stake 'clamp lila :to contactarm Mil. .Clamp Hi8y may herbent tte.d:;around shaftl to tightly conformithereto and be securely Llock'edf around.- the `shaft by: means .oban integrally formed look joint compressing .extensions .t I and vI |12; v.through which a threaded vmember ktelf `may be .passed -so` as `.to kiiiredly and l.

adjustably ,lcckthe clamp 165.3 around shaft 8-|`. Contact arm `spring |54 s may be moveahlyv linked to armv H3 by means of a rivet ||"5-. .In this manner. contact spring Mit may be angularly moved with respect to its `associated arm 'H33 vAt the end opposite the rivet, spring IM .has integrally formed thereto a wiper ||6 having a ici-shaped configuration and which :isvv sofshaped .as lto include a recess or groove into which-the turns'of-the conductor of ooil23 Vfit toallowfor smooth andxfriction freerelectrical contact .therealong'. Low vside terminal .3.8 vis connected to annular ring section :|52 orcontactassem'bly al by--means of a ball contact H3. formed in an integral fashion to low side contact spring t2@ whichgmayi-besta'hed to terminal 38 as at points #2| `and +22' thereof. .Ball ycontact H8 in this fashion is :resiliently adapted to smoothly -malze contactwith ring section |52.

AsLshaft 8 lxis rotated/.wiper orbrush |=||`rmoves over edge 65 of conductor @il making `good electrioal contact therewith and. is allowed -to traverse the entire spiralv conductor rbecause or" the angular link joint relationship formed between arm.A H3; and .contact spring Hll. The position of Thrush l? |15 along conductor 16o thus determines the amount of inductance oiered by thetuner coil. Further, sincea common shaft rotates each tuner contactor assembly, these sections are all rotatable or 'ganged together. A dust cover ISD having a plurality ofV side Walls-13|, |32 and flaps |36 fits over the clamp strap 39 and end plate |32 within the oonnes. of base flaps i439, itl .and ledges il and 8.9, ofbracket H. Cover itihas a plurality of slots |43cut therethrough so that 'the projections such as tt penetrating clamp strap '39 will also penetrate ,slots |133 as to be used to firm-ly stake the-coverthereon. In this fashionga tight dust cover is. provided ier Ythe entire assembly.

The tuner assembly, .thus-fnovelly constructed, provides amongst other features, an improved variable tuning device exhibiting novel jointed contacter linkage and also provides parallel positioning of closely spaced terminal strips which act to reduce the amount of inductance offered thereby. Further, in the operation thereof, the link-ed construction of the contacter assembly is adapted to afford a cancellation of inductance as the arms move back to each other. The subject invention provides a highly efcient tuner offering many constructional advantages, improvements and simplifications which allow the utilization of the tuner in quarters where space "6 ism-'at :a @premium :and `Jvvhere vsimplicity A.portenizls `economy.

Thexpresentinvention: of 1 a variable inductance tuningdevice iisfmerely illustrative and not ex- .haustivezirrscoperandA since many Widelydifierent Yempodimentsi'ofithe inventionsmay be madewithk out-departing from` thescope thereof, it yis intended :that .all matter contained in the above `description .and .shown .in the accompanying drawing shall be interpreted as'illustrative and :notinalimiting-sense.

Whatis claimed is:

vl. .1Aivariableinduotance tuning device having .enbase :plate includinga plurality of individual :rectangular cut-.out portions, a .plurality of .in- Achictaiicextunin'g elementsfthereior, each .of said elements including a terminal hase tta-ble within :leach of's'aid' cut-out portions, said base havinga .conguration lsuch that `a portion of .itsthiclznessiorms an upper levelhaving across- Isectionall diameterereater-.than thatof said cutout. portion, with.' saidlower partof said vthickness adapted to be snugly fitted within said out-.out portion. andto penetrate said base plate whereby a. .shoulder .is iron-med .onv said terminal base adapitedtofsltuate'the saineon the insideisurface ofisaldplate-,fa,plurality'ofslets out in saidlotver .portion 'of .said thickness, a nat insulative coil iorm having acircul'ar 'cross-section andan integral'ly :formed yestension depending therefrom, said extension forming a pair of shoulders with saidxciroula1`-cross-section, said shoulders adapted `to:sepambly resten-said shoulders of said terminalrbase withfsaid extension falling Within one ot said slots Vsoia-s to'hold` said-coil form in a. ytight .substantially `perpen'dicular manner on said 'terminal ibase `within said eut-out portions et :said base plate, said inductance tuning elements.- -eachrcomprising `a nat, ribbon conductcr havingfan:edgeret'aineizl by said coil form so as tosupport said conductor in-an edgewisefashicn, a pluralityfoffterminals lconnected to the ends ci' :said conductor Aadapted rtopenetrate other of saldi slots out in the said vterminal base, and means-.lor lvaryingy the electrical length of the conductornhetween said terminals so as to detern mine the amount for inductance vin said tuning device;

1.2; 'variable inductance tuning device having a baseplate including a rplurality of individual rectangular .cut-out portions, a plurality or in ductance tuning elements therefor, each of said elementszincludlng arterrnin'al base ttablewithin each .oisaidv cut--out `portioiissaid "base having a conigurati'onsu'ch. thatfa portion of its thickness forms/an vupper levelv Ahaving a cross-sectional diameter-:greater thanthat of said cut-out portion, Iwith said lower part of said thickness adaptedto l.be sin-:plyv ttedwithin Vsaid out-out portionand' vtoy penetrate said base plate whereby a; fshoulder isV formed on said terminal base adapted. toesituatethe same on the inside surface of said plate, a plurality of slot members cut in said lower portion of said thickness, a flat insulative coil form having a circular cross-seotion and an integrally formed extension depending therefrom, said extension forming a pair of shoulders with said circular cross-section, said shoulders adapted to separably rest on said rst shoulders of said terminal base with said extension falling Within said slots so as to hold said coil form in a tight substantially perpendicular manner on said terminal base within said cut-out portions of said base plate, said inductance tuning elements each comprising a flat, ribbon conductor having an edge retained by said coil form so as to support said conductor in an edgewise fashion, a plurality of terminals connected to the ends of said conductor adapted to penetrate other of said slots cut in the said terminal base, and means including a plurality of angularly displaceable conductor elements for varying the electrical length of the conductor between said terminals so as to determine the amount of inductance in said tuning device.

3. A variable inductance tuning device as in claim 2 wherein said means including a plurality of angularly displaceable portions has one of said portions connected to one of said terminals and the other voi said portion connected to the edge of said contactor opposite the edge retained by said base.

4. A variable inductive tuning device, as in claim 2, wherein said electrical insulative base has an aperture eut therethrough centrally and includes means for driving said angularly displaceable portion along the edge of said conductor.

5. A variable inductive tuning device7 as in claim 2, comprising means for iixedly connecting said driving means to one of said angularly displaceable portions and wherein one of said terminals is connected to said conductor at a point adjacent to said aperture and penetrates there through to the side of said base free of said conductor strip.

6. A variable inductance tuning device having a base plate including a, plurality of individual rectangular cut-out portions, a plurality of inductance tuning elements therefor, each of said elements including a terminal base ilttable within each of said cut-out portions, said base having a configuration such that a portion of its thickness forms an upper level having a cross-sectional diameter greater than that of said cut-out portion, with said lower part of said thickness adapted to be snugly tted within said cut-out portion and to penetrate said base plate whereby a shoulder is formed on said terminal base adapted to situate the same on the inside surface of said plate, a plurality of slot members cut in said lower portion of said thickness, a flat insulative coil form having a circular cross-section and an integrally formed extension depending therefrom, said extension forming a pair of shoulders on meeting said circular cross-section,

said shoulders `adapted to rest on said rst shoulders `of said terminal base and said extension falling within said slots so as to hold said coil form in a. tight substantially perpendicular manner on said terminal base within said cut-out portions of said base plate, said inductance tuning elements each comprising a ilat conductor having an edge retained by Said coil form so as to support said conductor in an edgewise fashion, a plurality of terminals connected to the ends of said conductor adapted to penetrate other of said slots cut in the said terminal base; and plural hinged means folding back on each other for varying the electrical length of the conductor between said terminals so as to determine the amount of inductance in said tuning device, said hinged means having an integrally formed U-shaped brush connected thereto adapted to ride upon the outer surface 'of said ilat conductor.

7. A variable inductance tuning device having a base plate including a plurality of individual rectangular cut-out portions, a plurality of inductance tuning elements therefor, each of said elements including a terminal base ttable Within each of said cut-out portions, said base having a configuration such that a portion of its thickness forms an upper level having a cross-sectional diameter greater than that of said cut-out portion, with said lower part of said thickness ladapted to be snugly fitted within said cut-out portion and to penetrate said base plate whereby a shoulder is formed on said terminal Vbase adapted to situate the same on the inside surface of said plate, a plurality of slot members cut in said lower portion Iof said thickness, a flat insulative coil form having a circular crossesection and an integrally formed extension depending therefrom, said extension forming a pair of shoulders on meeting said circular cross-section, said shoulders adapted to rest on said rst shoulders of said terminal base and said extension falling Within said slots so as to hold said coil form in a tight substantially perpendicular manner on said terminal base within said cut-out portions of said base plate, said inductance tuning elements each comprising a flat conductor having an edge retained by said coil form so as to support said conductor in an edgewise fashion, a plurality of terminals connected to the ends of said conductor adapted to penetrate other of said slots cut in the said terminal base, rotatable, plural hinged portions collapsible toward one another for varying the electrical length of the conductor between said terminals so as to determine the amount of inductance in said tuning device, and means for stopping the rotation of said hinged means between determined angular limits.

ROBERT J. AUST.

References Cited in the le of this patent UNITED STATES PATENTS Number 

